Note: Descriptions are shown in the official language in which they were submitted.
I
-- 2 --
UPHOLSTERED SEAT FOR CLEAN ROOM USE
Background of the Invention
The manufacture of microchips and some
other industrial products has created a necessity
for an extreme degree of cleanliness in manufacture
in facilities, commonly called clean rooms As result of these cleanliness requirements, Federal
standards have been promulgated and must be strictly
complied with by the industries involved. Current
Federal Standard No. 209B pertaining to classes of
room cleanliness establishes three classes of clean
rooms, Class 100 being the strictest of these Jo
classes. Class 100 specifies that only 100 particles
of 0.5 micron size or larger are allowed per cubic
foot of air in the clean room. The standard does
not pertain to merely an average foot ox air but to
any cubic foot, at any time. Suggested air veto-
cities are also listed for each class under Federal
Standard No. 209B.
A main object of the present invention
is to fully comply with and substantially exceed
the requirements of Class 100 under Federal Standard
No. 209B, in connection with upholstered furniture
for clean room use, such as chairs, stools and other
seat structures.
Presently, no conventional upholstered
furniture or wooden furniture can be tolerated in
clean rooms because of the micro particles expelled
by them into the environment during normal usage.
Such furniture falls far short of even the most
liberal class under Federal Standard No. 209B,
namely Class 100,000. Metal furniture, such as
furniture made entirely of stainless steel, can meet
the Federal standards but such furniture becomes
so uncomfortable during long usage as to be into--
enable, and does not represent a complete solution
to the problem.
,.~
;~Z~5~
A further object of the present invention
is to provide comfortable upholstered furniture,
including various types of seats for clean room
usage which fully comply with and exceed the clean-
lioness requirements under Federal standards or self-
imposed industrial standards.
Another object of the invention is to
provide seat cushions or seat backs in upholstered
forms which include sealed air-impermeable coverings
for the yielding cushions and hard base members
thereof, in conjunction with a highly efficient
filter element through which all air must flow when
leaving or entering the upholstered furniture struck
lure.
The filter element embodies in the invention
is either a hydrophilic or hydrophobic sheet element
possessing the ability to exclude particles as small
as 0.2 microns prom passing through the filter eye-
mints, thus exceeding substantially the require-
mints of Class 100 under Federal Standard No. 209B.
The sheet filter element is interposed
between the hard panel member of the seat or other
body support component of upholstered furniture and
the exterior air-impermeable cover. Breathing aver-
lures are provided in the hard panel member Andover which may be in registering or non-register-
in staggered relationship. In either case, air
leaving or entering the structure through the
breathing openings must also traverse the filter
element, thus preventing particle contamination of
the surrounding environment.
Other features and advantages of the in
mention will become apparent to those skilled in the
art during the course of the following detailed
description by reference to the accompanying drawings.
' ,;
~Z253 7(~1
-- 4 --
Brief description of the Drawings -
Figure 1 is a perspective view of an
upholstered chair for clean rooms according to the
present invention.
Figure 2 is an enlarged bottom plan view,
parts broken away, of the upholstered seat portion
of the chair in Figure 1
Figure 3 is a further enlarged vertical
section taken on line 3-3 of Figure 2.
Figure 4 is a further enlarged fragmentary
vertical section through the upholstered seat
: portion of the same plane as Figure 3.
Detailed De lotion -
Referring to the drawings in detail, wherein
like numerals designate live parts, a typical up-
holstered technician's chair lo for a clean room
according to the invention is shown in Figure 1.
The invention is equally applicable to other types
of upholstered clean room furniture, such as stools,
other types of chairs or benches. The chair 10 in
Figure 1 includes a metal pedestal 11, an uphold
; stored seat 12 attached to the pedestal, and an
upholstered backrest 13 adjustable attached to a
metal arm 14 rising from the seat 12. The invention
herein is embodied in the seat 12 and backrest Andy can be similarly embodied in any upholstered
furniture body supporting surface.
Figures 2, 3 and 4 showing the essence of
the invention depict in detail the structure of the
chair seat 12 in Figure 1. Substantially the
identical details apply to the backrest 13 or to any
body supporting portion of other upholstered foreign-
lure for clean rooms according to the invention.
The seat 12 comprises a substantially
rigid preferably contoured base panel member 15 of
wood or the like, on the upper face of which is
mounted a resilient cushion 16 of suitable material,
such as foam rubber or roam plastics material.
A filter element in the form of a sheet 17
of hydrophilic or hydrophobic material is applied
over the lower face of rigid panel member 15 and
near its margin is attached and sealed to the
member 15 by a continuous layer 18 of adhesive
sealant, Figure 4. The adhesive sealant extends
around the entire margin of the filter element 17
and precludes the passage of air outwardly or
inwardly between the element 17 and panel member 15.
The sheet filter element 17 may be formed
of hydrophilic material manufactured by German
Sciences, Inc., Ann Arbor, Michigan, under the
trademark VERSAPOR, Manufacturer I 9 No. V-200, or
their hydrophobic material, Manufacturer's No.
VOW. Similar material manufactured by other
companies may also be used This filtering medium
can preclude the passage there through of particles
as small as 0.2 microns. The particular material is
employed to substantially exceed the requirements
under Class 100 of Federal Standard No. 209B.
An air-impermeable preferably vinyl top
cover section 19 is stretched over the cushion 16
and base panel member 15, with a lower marginal
edge portion 20 thereof attached permanently to the
bottom face of the member 15 by a line of staples
21 or equivalent means. The edge 22 of top cover
section 19 is sealed to the sheet filter element 17
by a continuous bead 23, Figure 4, ox adhesive
air-impermeable sealant, so that air cannot pass
outwardly or inwardly between the element 17 and top
cover section 19.
A bottom cover section 24 of sheet vinyl
I; is applied over the bottom face of rigid panel
~Z~5~
member 15, and a double thickness marginal fold 25
of this bottom cover section is permanently attached
to the member 15 by parallel lines of staples 26
near the margin of the seat 12, to prevent air con-
lamination due to frayed edges
The rigid panel member 15 near its oppo-
site sides is provided with a pair of breathing
openings 27 extending completely there through.
similarly, the bottom cover section 24 has a pair
of breathing openings 28 formed there through. The
breathing openings 27 an 28 may be in registering
relationship on opposite sides of the element 17
or may be out of registration and staggered, as
illustrated. The non-registering arrangement of
the openings 27 and 28 possesses the advantage that
the sheet filter element 17 cannot readily be
punctured or damaged if an object is inserted in
the opening 28, because the element 17 is backed up
or reinforced by the hard member 15. When the
openings 27 and 28 are in registration, it would be
possible to rupture the element 17 were an object
inserted through an opening 28.
However, either arrangement of the breath-
in openings 27 and 28 is operationally satisfac-
tory, and in both cases air can enter the seat structure and be expelled therefrom only by passing
through the openings 27 and 28 and also through the
sheet filter element 17 disposed there between. In
the case of registering breathing openings, not
shown, the air passage is direct or axial with
respect to the openings 27 and 28, whereas in the
illustrated arrangement where the breathing openings
are non~r~gistering, the in flowing or outflowing
air passes through one breathing opening and then
along and through the filter element 17 to the
Sue
-- 7
other breathing opening on a zigzag path. It should
now be clear that no air can enter or exit the seat
structure on any other pathway due to the sealed
arrangement of the air-impermeable cover sections
19 and 24 and the sealed relationship of the element
17 with panel member 15 and top cover section 19.
In the embodiment shown in Figure 1, the
seat 12 is attached by screws 29 to a flange 30 of
the chair pedestal 11. These screws penetrate the
member 15 and are dipped in adhesive sealant before
installation. The lower cover section 24 can be
aperture at 31, Figure 2, adjacent to the screws 29.
The terms and expressions which have been
employed herein are used as terms of description and
not of limitation, and there is no intention, in the
use of such terms and expressions, of excluding any
equivalents of the features shown and described or
portions thereof but it is recognized that various
modifications are possible within the scope of the
invention claimed.
.,
